Summer might be just around the corner but a wintry blast is set to rip through the country this week bringing snow, "hurricane-force" winds and waves over nine metres.
MetService meteorologist Andrew James said the wild weather would begin on Tuesday afternoon in the South Island with a front dropping temperatures close to zero and dumping snow across the ranges.
Heavy snow watches were in place for Tuesday night about the Kaikōura Ranges, inland Canterbury and Otago with snow to 300m, and heavy falls above 500m.
MetService has issued road snow warnings overnight Tuesday for Lewis Pass, Arthurs Pass, Porters pass, Lindis Pass and the Crown Range Rd.
As the front moved on to the North Island Wednesday gale-force southwest winds would envelop most areas.
James said there was "high confidence" of severe west to southwest gales – over 85 kmh, with gusts even higher – from Northland, Auckland to Taranaki and eastwards to East Cape early Wednesday. Exposed parts of Wellington, Marlborough and Kaikōura would also be affected.
Widespread showers and periods of heavy rain across the North Island were also forecast ahead of the front on Wednesday.
The Auckland region would see southwesterly winds and some showers on Tuesday, before both the wind and rain picked up rapidly on Wednesday morning.
The North Island's west coast would also see southwest swells in excess of five metres, James said.
"This is going to be quite a significant event. On land we are warning people to take precaution from the high winds, don't leave anything loose outside. And at sea there are going to be some very large swells."
Weatherwatch NZ said these ocean swells could produce waves in excess of nine metres in places, driven by "hurricane-force winds" at times.
"This makes for dangerous marine and beach conditions along the western side of the country, in particular the western side of the North Island which is more exposed to this set-up.
"There will be rogue waves that may go higher too - so a warning in particular to Aucklanders who fish on the western rocks: this isn't a safe week to do so.
"It's not a safe week for boaties anywhere in the eastern Tasman Sea area or Cook Strait."
